Apparatus for the heating of ovens and the like



Oct. l, 1929. J. M. HARRISON APPARATUS FOR THE HEATING 0F ovENs 'AND THE LIKE 3 Sheets-Sheet INVENTOF' Filed Dec. 29, 1926 Oct. 1, 1929. 1. M. HARRISON 1,729,829

APPARATUS FOR THE HEATING 0F ovENs AND THE LIKE Filed Dec, 29. 1,926 3 Sheets-Sheet 2 wm, l

A v K y A N\ 'NVENTOR Oct. l, 1929. 1. M. HARRISON APPARATUS FOR THE HEATING OF OVENS AND THE LIKE Filed Deo. 29. 1926 5 Sheets-Sheet 3 n W Q N ATTORNEY Patented 4Oct. 1, 1929 UNITED STATES PATENT OFFICE JAMES M. mumrsomor CLEVELAND, oHIo APIPARATUS FOR THE HEATING F OVENS AND THE LIKE Application led December 29, 1926. Serial-No. 157,660.

larly to systems wherein the mixture of products of combustion and air is supplied to such Ovens or furnaces by means of a fan; a further object of the invention is to enable the purpose to be accomplished with a saving in expense as compared with that involved in existing practices.

The usual manner of applying productsof combustion to ovens of the ty e referred to by means of an induced-draft fini is substantially as follows Oilis burned within a combustion chamber having an incandescentrefractory lining or checker work therein, the oil being burned in suchl manner as to maintain such refractory material at incandeseence. This'incandescent condition enables the oil to be burned completely and also enables the combustible mixture of oil and air to be ignited by such incandescent lining or checker work, should a temporary interruption occur in the supply of oil and air to the chamber. As a necessary result of this mode of combustion, the gases leaving the combustion chamber are at a very high temperature. In order to supply. the drying oven with air and gas at t-he desired temperature, a cold air branch connection is made outside'the combustion chamber to the duct leading to the induced-draft fan. By pro- 40 viding such draft in this duct, the products of combustion leaving the combustion chamber at comparatively high temperatures as, for instance, 10000 F. are diluted to bring the temperature of the mixture entering the fan casing to a considerably lower'temperature,

as required, say approximately 600 F.

In the operation ofmy apparatus and in the practice of my process, a burner is employed which serves to atomize the oil and cni able the same to be burned in the combustion chamber without the aid of incandescent linings, baliles or checker Work. The temperature of the gases leaving the combustion chamber need not exceed 900 F.

Furthermore, instead of introducing cold air directly into the duct connecting the induced-draft fan with the combustion chamber, the air is drawn deliberately through the combustion chamber, whereby the temperature of the air is raised by contact with the flame andthe temperature of the products of combustion is lowered by direct mingling of the air and products of combustion within the combustion chamber, the temperature of the air being 'raised to the pro er extent by contacting with the flame and y contacting and intermingling. with the products of combustion, as well as by convection from hot surfaces and by radiation from the flame. The mixture is conducted directly from the combustion chamber to the fan and is delivered thence into the oven. Referring to the drawings, which illustrate the present preferred form of apparatus by which the process is realized, Fig. l represents a side elevation of the heater, oven and fan; Fig. 2 is a central vertical'sectional View through the heater; Fig. 3 is a sectional View corresponding substantially to the line 3-3 of Fig. 2, certain parts being broken away; Fig. 4 is a front elevation of the heater; and Fig. 5 a transverse vertical sectional view through the heater.

Describing the various parts by reference characters, A denotes the heating furnace generally, B the oven, and C the induceddraft fan, the central portion of which receives the heated air and products of combustion discharged from the furnace through the duct D, the fan delivering such mixture through the duct E into the oven B.

The heater or furnace is provided with metal sides 1 and a metal top 2, thetop being shown as strengthened by angle. irons 3 having their vertical flanges placed baek to back and suitably united. The metal top 2 extends beyond the sides l, and the angles between the top and sides are strengthened b v the angle irons 4. Above the bottom of each side 1 and fastened thereto is a Z bar 5, the bars 7 denotes the metal front wall and 8 thel metal rear wall of the furnace, the front wall being shown as strengthened by vertical angle irons 7a and 7b placed back to back and the rear wall being shown as strengthened in like manner by vertical angle irons 8a and 8b also placed back to back. The top of the front wall 7 is also provided with transverse angle irons 7c and 7 d, the former angle iron assisting to support the metal top 2. The rear wall 8 is provided with an angle iron 8c near the top and assisting to support the top plate 2.

Secured above the bottom of the rear wall 8 and projecting inwardly therefrom is the angle iron 8d which assists in supporting the lining 9 of insulating material, there being a similar lining within the front wall 7. The

. walls 1, 2, 7 and 8 and the lining constitute an outer shell for the furnace'. Within the linings 6 and spaced inwardly from the walls 1 are the metal walls 10, said walls vrunning the full length of the heater and having their outer ends secured between flanges of the angle irons 727h and 8a, 8". Each wall 10 is provided at its bottom with an angle iron 10a forming part of the footing for the furnace. Above the angle ironsl 10" are angle irons 10b which support cross bars 11, these cross bars in turn supporting the refractory slabs 12 constituting the bottom of the corn-l bustion chamber. The angle irons 1()h also i support the refractory slabs 13 constituting the side walls of the combustion chamber,

the said side-wall slabs being also supported by the metal sides 10. The slabs 13 are provided with suitable brackets 14; which support slabs 15 resting thereon and extending transversely of the combustion chamber at the rear thereof and engaging with their ends the slabs 13. The slabs 13 are also provided with brackets l13a which are adapted to support the upwardly arched refractory slabs 16 extending transversely of the combustion chamber and constituting a bale located be` low the roof of the casing.

Extending across the top of the combustion chamber, above the arches 16, are the refractory roof slabs 17, said slabs being supported on top of the side slabs 18, which constitute an extension of the slabs 13. Within the insulating vwalls 9- are the rear wall 19 and front wall 20, respectively, of the combustion chamber, the said walls also being of refractory material, preferably slabs of the type employed for the other walls of the said chamber.

Extending from the rear of the combustion chamber is the connection 21 from which the duct D extends to the fan C. This connection projects inwardly through the walls 9 and 19 and communicates with the rear of the chamber G above the combustion chamber proper indicated at F, the chamber F being separated from the outlet by a transverse wall 22 of refractory material resting upon one of the slabs 15 and extending upwardly to the rear arch 16.

Secured to and depending from each of the angle irons l()b and projecting inwardly therefrom is a Z bar 23, the bottom flanges of the. bars projecting toward each other and the innerY edge of each such flange being approximately in the plane of the side edge of the bottom wall 12 of the combustion chamber.

Between each lateral edge of the bottom 12 and the side wall 13 adjacent thereto is a slot 24.

The front of the heater is provided with a burner plate 27 the said plate having a pair of frusto-conical sleeves 271 projecting inwardly therefrom, each extending into the outer end ofV a. burner tile 28. Projecting into each of the sleeves 27a is a burner 29 of the atomizing type, each such burner having an oil supply 30 and a steam or air supply 31.

It will be noted that a Wide port 32 is provided at the front of the heater and along the sides thereof below the burner plate, for the supply of air beneath the bottom tiles 12 of the combustion chamber.. Below the roof 17 of the combustion chamber the front wall is provided with a peep hole 33.

With the parts constructed and arranged as described, the burners will be operated in the usual manner, delivering a combustible mixture of air and combustible fluid into the combustion chamber, the mixture being ignited and burned in the usual manner. Owing to the type of burners employed, it will be unnecessary to employ in my heater, checker work, baffles, or other arrangement of refractory material intended to be heated to incandescence; and it will be unnecessary to heat the combustion chamber to any such incandescent temperature in order to secure the proper functioning of the furnace for the purposes of my invention. Air admitted through the port 32 will be distributed by the Z bars 23 and the slots 24 into the bottom of the combustion chamber, at each side thereof. i As the air rises, it comes into contact with the flames of the burners and is heated thereby by convection and by the products of combustion, with which it mingles. An intimate mixture of the air and products is formed within the chambers YF and G and is delivered from the latter chamber through the outlet connection 21 into the duct D.

By the operation of the apparatus described herein, air for diluting the products of combustion is supplied directly to the combustion chamber; is heated by convection and by the flames from the burners therein; is mingled therein with the products of combustion; and the mixture thus formed is outlet from the combustion chamber at the 'heated fluid adapted for use in ovens for yenameling and other purposes, and am able to accomplish this result without the necessity for any special type of burner or for a.

special and expensive type of combustion chamber.

Having thus described my invention, what I claim is l. A furnace of the character described comprising an outer metallic shell, a lining of insulating material within said shell', refractory material within the said shell arranged to form a combustion chamber, there being metal side walls for said' refractory material and interposed between the same and the side insulating Walls, the said combustion chamber being provided vwith transverse arches below the top thereof and supported from the side walls, there being an rear end thereof and communicating with the space between said arches and the top of the combustion chamber. f

2. A furnace of the character described comprising a surrounding casing, a combustion chamber within said casing, the said combustion chamber comprising side, top and bottom walls of refractory material, the side walls being provided with brackets below the top thereof, longitudinally-spaced arched slabs supported by said brackets and forming with the top a chamber communieating directly with the combustion chamber throughout the major portion of thelength of the latter, a refractory slab extending across the rear of the combustion chamber below the arched slabs, a transverse slab forming with such refractory slabl and one of the arched slabs a barrier between the combustion chamber and the space thereabove, there being-an outlet for gases of combustion at the rear of the combustion chamber and communicating with said chamber above said barrier. i

3.- A furnace of the character described comprising a surrounding casing, a combustion chamber within said casing, the said combustion lchamber comprising side, top and bottom walls of refractory material, longitudinally spaced arched slabs extending across the combustion chamber and forming with the top a chamber communicating directly with the combustion 'chamber throughout the major portion of the length of the latter, refractory materialv extending across the rear of the combustion chamber below the arched slabs, a transverse slab forming with such refractory material and one of the arched slabs a barrier between the c-ombustion chamber and the space thereabove, there being an outlet for gases of combustion at .the rear of the combustion chamber and communicating with said chamber above said barrier.

4. A furnace of the character described comprising a surrounding casing, a combustion chamber within said casing, the said combustion chamber comprising side, top and bottom walls of refractory material, the side Walls being provided with brackets below the top thereof, longitudinally-spaced arched slabs-'supported by said brackets and forming with the top a chamber communicating. directly'with the combustion chamber throughout the major portion of the length of the latter, a refractory slab extending across the rear of the combustion chamber below the arched slabs, a transverse slab forming with such refractory slab and one of the arched slabs a barrier between the combustion chamber and the space thereabove, there being an outlet for gases of combustion at the rear of the combustion chamber and communicating with said chamber above said barrier, said combustion chamber being provided with a slot in the bottom thereof and adjacent each side wall, each slot extending substantially the full length of the combustion chamber.

5. A furnace of the character described comprising an outer shell, a lining of insulating material within said shell, refractory material within the said shell arranged to form a combustion chamber, there being metal side walls for said refractory material interposed between the same and the side insulating walls, the said combustion chamber being provided with transverse arches below the top thereof and supported from the side walls, therebeing an outlet from the combustion chamber communicating with the space between said arches and the top of the combustion chamber.

6. A furnace for a system or apparatus of the characterspecified consisting of a combustion chamber, one or more burners for dclivering a mixture of fluid fuel and a-ir into the said combustion chamber, the said combustion chamber having walls of refractory material and provided with slots in the boting one or more slots therein extending substantially the full length thereof for the upward flow of air into the lower compartment, an outlet leading from the'upper compartment and one or more burners for delivering a mixture of Huid fuel and air into the lower compartment, the said casing being provided with a lining of refractory material.

8. A furnace of the character described comprising a surrounding casing, refractory material within said casing and arranged to form a combustion chamber, a partition ,arranged within said combustion chamber and dividing the same into upper and lower compartments, said partition having one or more slots therein connecting said upper and lower compartments, the bottom of said combustion chamber having one or more slots extending substantially the full length of the combustion chamber for the upward flow of air to the said combustion chamber and into the `flame and products of combustion, an outlet leading from said upper compartment and one or more burners for delivering a mixture of fluid fuel and air into the said combustion chamber.

In testimony whereof, I hereunto affix my signature.

JAMES M. HARRISN 

